Abstract: A system and method for measuring energy harvested from at least one energy source for use in an access control system. The method comprises charging a capacitive storage device to a voltage high threshold, where the capacitive storage device is for storing energy harvested from at least one sensor receiving energy from at least one energy source and the capacitive storage device is coupled to an energy harvesting manager adapted for managing the amount of energy received by the at least one sensor, and applying a reference load to the capacitive storage device until the capacitive storage device discharges to a predetermined voltage value, the reference load having a predetermined resistance value.

Abstract: An electronic lock with power failure control circuit includes a lock mechanism having a latchbolt movable between extended and retracted positions and an electrically powered lock actuator to lock and unlock the latchbolt. The power failure control circuit includes a microcontroller and the lock is connected to a primary power source and an auxiliary power source, preferably supercapacitors and charger that can be turned on by the microcontroller and off when the charger signals a full charge. A power monitor circuit detects low voltage on the primary power supply and sets a power failure interrupt causing the microcontroller to execute power failure instructions that control the actuator so that the lock is placed into a desired locked or unlocked final state during the power failure. Upon detection of the return of good power, the system resets the lock.

Abstract: A method for measuring energy harvested from at least one energy source for use in an access control system, comprising providing an access control device adapted to be at least partially powered by energy harvested from at least one energy source; providing at least one sensor receiving energy from the at least one energy source; providing an energy harvesting manager coupled to the at least one sensor, wherein the energy harvesting manager manages the amount of energy received by the at least one sensor; providing a capacitive storage device coupled to the energy harvesting manager, the capacitive storage device for storing energy harvested from the at least one sensor; charging the capacitive storage device to a voltage high threshold, V-HTH; applying a reference load to the capacitive storage device until the capacitive storage device discharges to a predetermined voltage value, Vo/e, the reference load having a predetermined resistance value; determining a time constant, the time constant defined as the